Practice Problems: Load Analysis Dead, Live, Wind, Seismic
Question 1
A structural engineer is designing a three-story office building and needs to calculate the total dead load for a typical floor. The floor system consists of a 5-inch thick normal-weight concrete slab, 1-inch thick lightweight concrete fill for leveling, ceramic floor tiles (3/4-inch thick), and a suspended ceiling system. Given the following unit weights:
Normal-weight concrete: 150 pcf
Lightweight concrete: 110 pcf
Ceramic tiles: 10 psf
Suspended ceiling: 4 psf
Mechanical/electrical allowance: 3 psf
What is the total dead load per square foot for this floor system?
(a) 89 psf
(b) 92 psf
(c) 95 psf
(d) 98 psf
Question 2
A structural engineer is evaluating the live load reduction for an interior column supporting multiple floors in an apartment building. The column supports a tributary area of 450 square feet at each floor level and extends from the foundation through 8 floors. Using ASCE 7, the unreduced floor live load for residential occupancy is 40 psf. The live load element factor KLL = 2 for interior columns.
What is the reduced live load for this column design?
(a) 18.0 psf
(b) 20.0 psf
(c) 22.4 psf
(d) 25.0 psf
Question 3
A civil engineer is designing a warehouse building with a roof structure supporting mechanical equipment. The roof has a slope of 1:12 and the specified flat roof live load is 20 psf. A rooftop mechanical unit weighing 8,000 lbs is concentrated over a 4 ft × 5 ft area.
Per ASCE 7, what is the total design load intensity (dead load not included) that should be considered in the design, given that the roof slope allows for reduction?
(a) 400 psf
(b) 420 psf
(c) 440 psf
(d) 460 psf
Question 4
A structural engineer is analyzing wind loads on a 150-ft tall rectangular office building located in Dallas, Texas (Exposure C). The building dimensions are 100 ft × 80 ft in plan. Using ASCE 7, the basic wind speed is 115 mph (3-second gust), Risk Category II, with Kd = 0.85, Kz at 150 ft = 1.09, and Kzt = 1.0.
What is the design wind pressure (qz) at the top of the building using the velocity pressure equation?
(a) 28.4 psf
(b) 30.2 psf
(c) 32.6 psf
(d) 35.1 psf
Question 5
A civil engineer is designing the foundation for a building in a seismic region with the following parameters: SDS = 0.75g, SD1 = 0.50g, Risk Category III, and the building has a special reinforced concrete shear wall system. The building has 6 stories with a total seismic weight of 12,000 kips and a fundamental period T = 0.8 seconds.
What is the seismic response coefficient Cs using ASCE 7 provisions (R = 6, Ie = 1.25)?
(a) 0.104
(b) 0.125
(c) 0.156
(d) 0.175
Question 6
A structural engineer is calculating the snow load on a flat roof of a hospital building in Minneapolis, Minnesota. The ground snow load pg = 50 psf, the roof is unobstructed and fully exposed (Ce = 0.9), has a heated interior (Ct = 1.0), and is Risk Category IV (Is = 1.2). The roof is essentially flat with a slope of 1/4:12.
What is the design flat roof snow load pf?
(a) 42 psf
(b) 45 psf
(c) 48 psf
(d) 54 psf
Question 7
A structural engineer is designing a simply supported steel beam spanning 30 feet in an office building. The beam supports a 12-ft tributary width. The dead load includes the beam self-weight (80 plf), a 6-inch concrete slab (75 psf), and miscellaneous ceiling/MEP loads (15 psf). The live load for office occupancy is 50 psf with no reduction permitted for this member.
What is the total factored uniform load on the beam using LRFD Load Combination 2 (1.2D + 1.6L)?
(a) 2.58 kips/ft
(b) 2.74 kips/ft
(c) 2.90 kips/ft
(d) 3.12 kips/ft
Question 8
A civil engineer is evaluating wind loads on a billboard structure 40 feet tall and 20 feet wide, located in an open area with Exposure D. The basic wind speed is 120 mph (3-second gust), Risk Category II. Using ASCE 7 for Other Structures, the force coefficient Cf = 1.8 for the sign, Kz = 1.27 at the centroid height, Kzt = 1.0, and Kd = 0.95.
What is the total horizontal wind force on the billboard?
(a) 54.2 kips
(b) 58.7 kips
(c) 62.4 kips
(d) 66.8 kips
Question 9
A structural engineer is designing a parking garage with a post-tensioned concrete slab. The slab thickness is 8 inches of normal-weight concrete, and additional dead loads include a 2-inch topping slab (150 pcf) and a waterproofing membrane (3 psf). The vehicle live load for passenger cars is 40 psf per ASCE 7.
What is the total unfactored dead load on the slab?
(a) 103 psf
(b) 106 psf
(c) 109 psf
(d) 112 psf
Question 10
A civil engineer is determining the equivalent lateral force for seismic design of a 10-story steel moment frame building. The building has SDS = 1.0g, SD1 = 0.60g, Risk Category II (Ie = 1.0), R = 8, and total seismic weight W = 18,000 kips. The calculated fundamental period using approximate method is Ta = 1.2 seconds.
What is the seismic base shear V using ASCE 7?
(a) 1,125 kips
(b) 1,350 kips
(c) 1,575 kips
(d) 2,250 kips
Question 11
A structural engineer is analyzing a continuous beam supporting library stack areas in a university library. The beam has a tributary area of 320 square feet. The unreduced live load for library stack rooms is 150 psf per ASCE 7. The beam is part of a floor system with multiple levels of stacking.
Can live load reduction be applied to this beam, and if so, what is the reduced live load?
(a) No reduction permitted; use 150 psf
(b) Reduced to 135 psf
(c) Reduced to 120 psf
(d) Reduced to 105 psf
Question 12
A civil engineer is designing a canopy structure projecting 15 feet from a building wall. The canopy is located in Miami, Florida with a basic wind speed of 175 mph (ultimate design) and Exposure C. Using ASCE 7 provisions for open buildings and structures, the net pressure coefficient for the canopy upper surface CN = 1.2 (upward). At height z = 20 ft, Kz = 0.98, Kzt = 1.0, Kd = 0.85.
What is the design uplift wind pressure on the canopy?
(a) 68.2 psf
(b) 74.5 psf
(c) 82.3 psf
(d) 91.6 psf
Question 13
A structural engineer is evaluating the rain load on a flat roof with a primary drainage system and secondary (overflow) scupper system. The roof area is 5,000 square feet with a flow rate capacity of 10 gpm per drain. There are 4 primary drains installed. The static head at the secondary drainage level is 4 inches. Using ASCE 7, the rainfall rate for a 1-hour duration storm is 3 inches/hour.
What is the design rain load R on the roof?
(a) 5.2 psf
(b) 15.6 psf
(c) 20.8 psf
(d) 26.0 psf
Question 14
A civil engineer is designing a steel truss supporting a roof with a 6:12 slope in a convention center. The horizontal span is 80 feet, and the tributary width is 20 feet. The dead load includes roofing (8 psf), metal deck (3 psf), insulation (2 psf), and truss self-weight estimated at 12 psf. The roof live load is 20 psf on the horizontal projection.
What is the total design load on one bottom chord panel point if panel points are spaced at 10-foot intervals horizontally?
(a) 8.5 kips
(b) 9.0 kips
(c) 10.5 kips
(d) 12.0 kips
Question 15
A structural engineer is analyzing seismic design forces on a 4-story masonry bearing wall building. The building has a seismic weight of 5,000 kips, SDS = 0.50g, SD1 = 0.30g, Risk Category II (Ie = 1.0), and uses special reinforced masonry shear walls (R = 5). The approximate fundamental period Ta = 0.4 seconds. Seismic Design Category D applies.
What is the minimum seismic base shear V that must be used?
(a) 220 kips
(b) 375 kips
(c) 500 kips
(d) 625 kips
Question 16
A civil engineer is evaluating a pre-engineered metal building with rigid frames spaced at 25 feet on center. The roof slope is 1:12, and the building is located in Chicago with a ground snow load pg = 25 psf. The building is heated (Ct = 1.0), partially exposed (Ce = 1.0), Risk Category II (Is = 1.0), and the roof is unobstructed.
What is the design sloped roof snow load ps considering the thermal factor and slope reduction?
(a) 15.8 psf
(b) 16.6 psf
(c) 17.5 psf
(d) 18.2 psf
Question 17
A structural engineer is designing a concrete slab-on-grade for a retail store with an anticipated floor loading from merchandise displays. The slab will support uniformly distributed display racks. The specified retail live load per ASCE 7 is 100 psf, and the slab has a supported tributary area of 800 square feet for design purposes.
What is the reduced live load for the slab design using the live load reduction provisions?
(a) 75 psf
(b) 87 psf
(c) 100 psf
(d) 112 psf
Question 18
A civil engineer is calculating lateral wind forces on a rectangular building 200 ft long, 100 ft wide, and 60 ft tall. The building is located in Exposure B with V = 110 mph, Risk Category II, Kd = 0.85. Using the simplified procedure, the net pressure coefficient for the windward wall at mean roof height is being calculated with Kz = 0.70 and Kzt = 1.0.
What is the velocity pressure qh at mean roof height?
(a) 18.2 psf
(b) 20.4 psf
(c) 22.8 psf
(d) 25.6 psf
Question 19
A structural engineer is evaluating the vertical distribution of seismic forces on a 6-story concrete frame building. The seismic base shear V = 800 kips has been calculated. The weights and heights of each floor above the base are: Floor 1 (15 ft, 1200 kips), Floor 2 (27 ft, 1200 kips), Floor 3 (39 ft, 1200 kips), Floor 4 (51 ft, 1200 kips), Floor 5 (63 ft, 1200 kips), Roof (75 ft, 1000 kips).
What is the lateral seismic force Fx at the roof level?
(a) 198 kips
(b) 215 kips
(c) 232 kips
(d) 248 kips
Question 20
A civil engineer is designing foundation walls for a commercial building that will be subjected to lateral soil pressure and surcharge loads. The wall retains 12 feet of soil with a unit weight of 120 pcf and an equivalent fluid pressure of 35 pcf. Additionally, a uniform surcharge load of 250 psf from adjacent pavement exists at the ground surface behind the wall.
What is the total lateral force per linear foot acting on the foundation wall at its base due to soil and surcharge?
(a) 2.82 kips/ft
(b) 3.24 kips/ft
(c) 3.78 kips/ft
(d) 4.12 kips/ft
